High-Speed RF Switch Electronics for Picking Up of Electron–Positron Beam Bunches

Beam diagnostics is important to guarantee good quality of beam in a particle accelerator. Both the electron and positron run in the tunnel in some modern electron-positron colliders such as circular electron-positron collider (CEPC) to be built and Beijing Electron-Positron Collider II (BEPC II). To measure the electron and positron beams, picking-up these two different bunches in real time is a notable concern. As the time interval between adjacent electron and positron bunches is quite small, for example, 6 ns in CEPC, high-speed switch electronics is required. This paper presents the prototype design of a high-speed radio frequency (RF) electronics that can pick up nanosecond positron-electron beam bunches with a switching time of fewer than 6 ns. Fast separation of electron and positron is achieved based on RF switches and precise delay adjustment of the controlling signals (~10 ps). Initial tests have been conducted in the laboratory to evaluate the performance of electronics; the results indicate that this circuit can successfully pick up the bunch signal within a time interval of 6 ns, which makes it possible to further measure the electron and positron beams simultaneously.